Fenestra cochleae

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Section through a human temporal bone with fenestra cochleae (No. 8)

The fenestra cochleae (Latin; literally "window of the snail") or the round window ( Fenestra rotunda ) is a part of the ear of the terrestrial vertebrate. It connects the scala tympani of the inner ear with the middle ear .

Together with the organ of equilibrium, the cochlea forms a cavity that is essentially filled with fluids (peri- and endolymph) and is almost completely embedded in bone. Sound waves are transmitted into this system through the oval window. Since liquids can hardly be compressed and the system cannot expand due to the bony embedding, a second opening, the round window, serves to equalize pressure.

In detail: The sound waves hit the eardrum , which transmits the vibration to the ossicular chain in the middle ear; as the last link, the footplate of the stapes and the associated fenestra vestibuli ( oval window ) are moved. This causes the perilymph in the vestibule ( scala vestibuli ) to vibrate. This is connected to the tympanic cavity via the helicotrema , so that its fluid moves in the opposite direction. The Fenestra cochleae serves to equalize pressure.

The fenestra cochleae or rotunda (round window) and above it the fenestra ovale or vestibuli (oval window)

literature

Individual evidence

  1. Frick special anatomy: Systematics of muscles and ducts Georg Thieme Verlag 1992, page 423, ISBN 313356904X
  2. Schünke Prometheus: Learning Atlas of Anatomy Georg Thieme Verlag 2006, page 151, ISBN 3131395419